--Tasmania Wind-Diesel Project (fwd)

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From: ENVIRO@salata.com (Environmental News)
Date: 29 Nov 96 18:36:38 
Newsgroups: alt.save.the.earth
Subject: --Tasmania Wind-Diesel Project
Organization:  Environmental News 
Lines: 160

by David Coote

     During the past 30 years Tasmania's Hydro-Electric
Commission (HEC) has been the target of vociferous criticism over
its environmental record.  Many magnificent wilderness areas now
lie buried under the water reservoirs used by the HEC to generate
electricity. The HEC has stated that the era of building large
dams is now past and that any major addition of electricity
generation capacity is likely to focus on wind power. The King
Island Wind Power project, scheduled for installation next year,
is set to be the first step of this welcome change in direction.

     King Island lies in Bass Strait between the Australian
mainland and Tasmania, which is an island state. The HEC
currently produces power on King Island using diesel generators
with a total capacity of around 4 MW. In November, 1994, the
island's population of about 1,800 were using about 11.2 million
kWh/year with an overnight peak load of around 1 MW and peak
daytime load of about 2.8 MW.  Keen to reduce the money spent on
subsidizing the price of power to mainland levels, the HEC in
1993 ran a "Pre-Feasibility Study into electricity generation
fuel savings for King Island". After examining a variety of
options including cogeneration, wave and mini-hydro, the study
selected wind as the most economic alternative.

     Robert Stewart, HEC Project Engineer for the proposed
system, says the Huxley Hill wind farm is expected to save
[A]$360,000 per year in fuel costs. King Island customers
currently pay "a network charge of [A]36 cents/day and
an energy charge of [A]14.48 cents/kWh."  Even at these high
prices, Stewart says, customers on King Island are supplied
electricity at a subsidized rate.

     The island offers a magnificent wind regime. Stewart says
the average wind speed at the Huxley Hill site is "7.3 m/s [16
mph] at 10 m . . . and 9.2 m/s [21mph] at 30 m." These excellent
winds are part of the prevailing westerlies that speed along the
southern coast of Australia in latitudes often colloquially
referred to as the "roaring forties".  Wind power production is
further facilitated by the wind speed profile.  Monitoring
conducted at nearby Mary Hill since 1978 and at Huxley Hill since
March 1994 indicates the wind speed drops below 3.5 m/s [8 mph]
for only about 10% of the time and rises above 25m/s [56 mph] for
only around 1%. This is a good fit with typical cut-in and
cut-out speeds on a modern wind turbine.

     While the pre-feasibility study indicated that up to five
225-kW turbines would be economically viable, the HEC, citing
grid reliability concerns, has decided to restrict the initial
installation to three units.  Analysis of the expected
reliability from the mixed wind-diesel hybrid generation system
carried out by the HEC has led to several other recommendations.
These include using three smaller turbines rather than one large
unit, no more than 40% wind penetration, spinning reserve to
cover total loss of wind generation, and minimum diesel plant
loading of 30% to 40% of full load.  A paper presented at the
1995 Australia-New Zealand Solar Energy Society (ANZSES) annual
conference by Keith Caney of the HEC goes on to say that if "wind
penetration is to be increased beyond 40% then light-loading of
the diesels becomes an important consideration."  Caney adds that
diesel engines can be modified to alleviate this problem.  The
paper mentions that the HEC examined battery/inverter systems to
allow grid support for "transient periods of inadequate
generation until extra diesel generation is brought on line" but
rejected this as currently too expensive.

     Remote locations like King Island bring maintenance problems
all their own.  Stewart says that estimated down time for wind
turbines on King Island is expected to be higher than the average
turbine located in less remote parts of Europe where maintenance
facilities and servicing organizations" are more readily
accessible.  Stewart also estimates that the turbines will
"suffer energy losses due to turbine wake losses, soiled blades
and parasitic energy losses" up to about 4%. He says the
availability of the windfarm will be about 94% with a capacity
factor of between 33% and 40%, depending on the penetration. He
points out that connected to a larger grid "the capacity factor
could be 44%." The windfarm will provide 18% of the total energy
used within the grid although Stewart says this "may be increased
to 21% after further research and development."

     In addition to its technical review, the HEC hasn't ignored
other aspects of wind development, including bird strike,
residents' concerns, and archaeological and visual impact. To
make the turbines more visible to birds, the blades will be
painted white with dark colored tips. A consultant called in as
part of the Environmental Impact Assessment (EIA) concluded "that
the turbines are not considered to be a significant hazard to
birdlife," adding that if any birds die in collisions, the
"carcasses should be removed from the vicinity to avoid
attracting birds of prey".  Tasmanian Aboriginal Land Council
consultant Darrell West indicated that the areas proposed for the
development were not of significance to the Aboriginal community.
The EIA doesn't mention any serious objections from local
residents, and the turbines will be marketed as a tourist

     Stewart says the Tasmanian government has formally approved
the project and is expected to proceed with a 19-month design and
construction programme, with tenders issued for the turbines in
either June or July. The project should be completed in late

     Many wind power industry observers feel these wind-diesel
hybrid systems have a bright future in island and remote grids
generally.  In addition to  large reductions in carbon dioxide
emissions--750 kilograms (1600 pounds) per 1,000 kWh avoided from
the distillate diesel fuel used on King Island--they offer
significant cost savings.

     Certainly there seems scope for a much wider adoption of
hybrids in Australia. Western Power operates roughly 30
mini-grids in Western Australia and the HEC has discrete grids on
Flinders and King Islands.  Stewart notes that the HEC has
purchased power since 1988 from a privately owned 55-kW
wind-turbine on Flinders Island (also located in Bass Strait). 
With the experience gained from wind-monitoring since 1978
coupled to the King Island project, Stewart says the HEC is in a
good position to compete for similar work.

[Editor's Note: David Coote is a free-lance writer residing in

@1996 David Coote


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